✨ configurable controller replicas and master node selector

pkg/cmd/hub/operator.go

@@ -22,6 +22,11 @@ func NewHubOperatorCmd() *cobra.Command {
 
 	flags := cmd.Flags()
 	flags.BoolVar(&cmOptions.SkipRemoveCRDs, "skip-remove-crds", false, "Skip removing CRDs while ClusterManager is deleting.")
+	flags.StringVar(&cmOptions.ControlPlaneNodeLabelSelector, "control-plane-node-label-selector",
+		"node-role.kubernetes.io/master=", "control plane node labels, "+
+			"e.g. 'environment=production', 'tier notin (frontend,backend)'")
+	flags.Int32Var(&cmOptions.DeploymentReplicas, "deployment-replicas", 0,
+		"Number of deployment replicas, operator will automatically determine replicas if not set")
 	opts.AddFlags(flags)
 	return cmd
 }

pkg/cmd/spoke/operator.go

@@ -34,6 +34,11 @@ func NewKlusterletOperatorCmd() *cobra.Command {
 	cmd.Flags().BoolVar(&klOptions.SkipPlaceholderHubSecret, "skip-placeholder-hub-secret", false,
 		"If set, will skip ensuring a placeholder hub secret which is originally intended for pulling "+
 			"work image before approved")
+	cmd.Flags().StringVar(&klOptions.ControlPlaneNodeLabelSelector, "control-plane-node-label-selector",
+		"node-role.kubernetes.io/master=", "control plane node labels, "+
+			"e.g. 'environment=production', 'tier notin (frontend,backend)'")
+	cmd.Flags().Int32Var(&klOptions.DeploymentReplicas, "deployment-replicas", 0,
+		"Number of deployment replicas, operator will automatically determine replicas if not set")
 	opts.AddFlags(flags)
 
 	return cmd

pkg/operator/helpers/helpers.go

@@ -432,7 +432,8 @@ func LoadClientConfigFromSecret(secret *corev1.Secret) (*rest.Config, error) {
 // - kube version: if the kube version is less than v1.14 reutn 1
 // - node: list master nodes in the cluster and return 1 if the
 // number of master nodes is equal or less than 1. Return 3 otherwise.
-func DetermineReplica(ctx context.Context, kubeClient kubernetes.Interface, mode operatorapiv1.InstallMode, kubeVersion *version.Version) int32 {
+func DetermineReplica(ctx context.Context, kubeClient kubernetes.Interface, mode operatorapiv1.InstallMode, kubeVersion *version.Version,
+	controlPlaneNodeLabelSelector string) int32 {
 	// For hosted mode, there may be many cluster-manager/klusterlet running on the management cluster,
 	// set the replica to 1 to reduce the footprint of the management cluster.
 	if IsHosted(mode) {
@@ -451,14 +452,14 @@ func DetermineReplica(ctx context.Context, kubeClient kubernetes.Interface, mode
 		}
 	}
 
-	return DetermineReplicaByNodes(ctx, kubeClient)
+	return DetermineReplicaByNodes(ctx, kubeClient, controlPlaneNodeLabelSelector)
 }
 
 // DetermineReplicaByNodes determines the replica of deployment based on:
 // list master nodes in the cluster and return 1 if
 // the number of master nodes is equal or less than 1. Return 3 otherwise.
-func DetermineReplicaByNodes(ctx context.Context, kubeClient kubernetes.Interface) int32 {
-	nodes, err := kubeClient.CoreV1().Nodes().List(ctx, metav1.ListOptions{LabelSelector: "node-role.kubernetes.io/master="})
+func DetermineReplicaByNodes(ctx context.Context, kubeClient kubernetes.Interface, controlPlaneNodeLabelSelector string) int32 {
+	nodes, err := kubeClient.CoreV1().Nodes().List(ctx, metav1.ListOptions{LabelSelector: controlPlaneNodeLabelSelector})
 	if err != nil {
 		return defaultReplica
 	}

pkg/operator/helpers/helpers_test.go

@@ -535,7 +535,7 @@ func TestDeterminReplica(t *testing.T) {
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
 			fakeKubeClient := fakekube.NewSimpleClientset(c.existingNodes...)
-			replica := DetermineReplica(context.Background(), fakeKubeClient, c.mode, c.kubeVersion)
+			replica := DetermineReplica(context.Background(), fakeKubeClient, c.mode, c.kubeVersion, "node-role.kubernetes.io/master=")
 			if replica != c.expectedReplica {
 				t.Errorf("Unexpected replica, actual: %d, expected: %d", replica, c.expectedReplica)
 			}

pkg/operator/operators/clustermanager/controllers/clustermanagercontroller/clustermanager_controller.go

@@ -58,8 +58,10 @@ type clusterManagerController struct {
 		mwctrEnabled, addonManagerEnabled bool) error
 	generateHubClusterClients func(hubConfig *rest.Config) (kubernetes.Interface, apiextensionsclient.Interface,
 		migrationclient.StorageVersionMigrationsGetter, error)
-	skipRemoveCRDs    bool
-	operatorNamespace string
+	skipRemoveCRDs                bool
+	controlPlaneNodeLabelSelector string
+	deploymentReplicas            int32
+	operatorNamespace             string
 }
 
 type clusterManagerReconcile interface {
@@ -84,6 +86,8 @@ func NewClusterManagerController(
 	configMapInformer corev1informers.ConfigMapInformer,
 	recorder events.Recorder,
 	skipRemoveCRDs bool,
+	controlPlaneNodeLabelSelector string,
+	deploymentReplicas int32,
 	operatorNamespace string,
 ) factory.Controller {
 	controller := &clusterManagerController{
@@ -92,14 +96,16 @@ func NewClusterManagerController(
 		patcher: patcher.NewPatcher[
 			*operatorapiv1.ClusterManager, operatorapiv1.ClusterManagerSpec, operatorapiv1.ClusterManagerStatus](
 			clusterManagerClient),
-		clusterManagerLister:      clusterManagerInformer.Lister(),
-		configMapLister:           configMapInformer.Lister(),
-		recorder:                  recorder,
-		generateHubClusterClients: generateHubClients,
-		ensureSAKubeconfigs:       ensureSAKubeconfigs,
-		cache:                     resourceapply.NewResourceCache(),
-		skipRemoveCRDs:            skipRemoveCRDs,
-		operatorNamespace:         operatorNamespace,
+		clusterManagerLister:          clusterManagerInformer.Lister(),
+		configMapLister:               configMapInformer.Lister(),
+		recorder:                      recorder,
+		generateHubClusterClients:     generateHubClients,
+		ensureSAKubeconfigs:           ensureSAKubeconfigs,
+		cache:                         resourceapply.NewResourceCache(),
+		skipRemoveCRDs:                skipRemoveCRDs,
+		controlPlaneNodeLabelSelector: controlPlaneNodeLabelSelector,
+		deploymentReplicas:            deploymentReplicas,
+		operatorNamespace:             operatorNamespace,
 	}
 
 	return factory.New().WithSync(controller.sync).
@@ -141,6 +147,11 @@ func (n *clusterManagerController) sync(ctx context.Context, controllerContext f
 		workDriver = clusterManager.Spec.WorkConfiguration.WorkDriver
 	}
 
+	replica := n.deploymentReplicas
+	if replica <= 0 {
+		replica = helpers.DetermineReplica(ctx, n.operatorKubeClient, clusterManager.Spec.DeployOption.Mode, nil, n.controlPlaneNodeLabelSelector)
+	}
+
 	// This config is used to render template of manifests.
 	config := manifests.HubConfig{
 		ClusterManagerName:      clusterManager.Name,
@@ -149,7 +160,7 @@ func (n *clusterManagerController) sync(ctx context.Context, controllerContext f
 		WorkImage:               clusterManager.Spec.WorkImagePullSpec,
 		PlacementImage:          clusterManager.Spec.PlacementImagePullSpec,
 		AddOnManagerImage:       clusterManager.Spec.AddOnManagerImagePullSpec,
-		Replica:                 helpers.DetermineReplica(ctx, n.operatorKubeClient, clusterManager.Spec.DeployOption.Mode, nil),
+		Replica:                 replica,
 		HostedMode:              clusterManager.Spec.DeployOption.Mode == operatorapiv1.InstallModeHosted,
 		RegistrationWebhook: manifests.Webhook{
 			Port: defaultWebhookPort,

pkg/operator/operators/clustermanager/options.go

@@ -23,7 +23,9 @@ import (
 )
 
 type Options struct {
-	SkipRemoveCRDs bool
+	SkipRemoveCRDs                bool
+	ControlPlaneNodeLabelSelector string
+	DeploymentReplicas            int32
 }
 
 // RunClusterManagerOperator starts a new cluster manager operator
@@ -75,6 +77,8 @@ func (o *Options) RunClusterManagerOperator(ctx context.Context, controllerConte
 		kubeInformer.Core().V1().ConfigMaps(),
 		controllerContext.EventRecorder,
 		o.SkipRemoveCRDs,
+		o.ControlPlaneNodeLabelSelector,
+		o.DeploymentReplicas,
 		controllerContext.OperatorNamespace,
 	)
 

pkg/operator/operators/klusterlet/controllers/klusterletcontroller/klusterlet_cleanup_controller.go

@@ -32,12 +32,14 @@ import (
 )
 
 type klusterletCleanupController struct {
-	patcher                      patcher.Patcher[*operatorapiv1.Klusterlet, operatorapiv1.KlusterletSpec, operatorapiv1.KlusterletStatus]
-	klusterletLister             operatorlister.KlusterletLister
-	kubeClient                   kubernetes.Interface
-	kubeVersion                  *version.Version
-	operatorNamespace            string
-	managedClusterClientsBuilder managedClusterClientsBuilderInterface
+	patcher                       patcher.Patcher[*operatorapiv1.Klusterlet, operatorapiv1.KlusterletSpec, operatorapiv1.KlusterletStatus]
+	klusterletLister              operatorlister.KlusterletLister
+	kubeClient                    kubernetes.Interface
+	kubeVersion                   *version.Version
+	operatorNamespace             string
+	managedClusterClientsBuilder  managedClusterClientsBuilderInterface
+	controlPlaneNodeLabelSelector string
+	deploymentReplicas            int32
 }
 
 // NewKlusterletCleanupController construct klusterlet cleanup controller
@@ -51,16 +53,20 @@ func NewKlusterletCleanupController(
 	appliedManifestWorkClient workv1client.AppliedManifestWorkInterface,
 	kubeVersion *version.Version,
 	operatorNamespace string,
+	controlPlaneNodeLabelSelector string,
+	deploymentReplicas int32,
 	recorder events.Recorder) factory.Controller {
 	controller := &klusterletCleanupController{
 		kubeClient: kubeClient,
 		patcher: patcher.NewPatcher[
 			*operatorapiv1.Klusterlet, operatorapiv1.KlusterletSpec, operatorapiv1.KlusterletStatus](klusterletClient).
 			WithOptions(patcher.PatchOptions{IgnoreResourceVersion: true}),
-		klusterletLister:             klusterletInformer.Lister(),
-		kubeVersion:                  kubeVersion,
-		operatorNamespace:            operatorNamespace,
-		managedClusterClientsBuilder: newManagedClusterClientsBuilder(kubeClient, apiExtensionClient, appliedManifestWorkClient, recorder),
+		klusterletLister:              klusterletInformer.Lister(),
+		kubeVersion:                   kubeVersion,
+		operatorNamespace:             operatorNamespace,
+		managedClusterClientsBuilder:  newManagedClusterClientsBuilder(kubeClient, apiExtensionClient, appliedManifestWorkClient, recorder),
+		controlPlaneNodeLabelSelector: controlPlaneNodeLabelSelector,
+		deploymentReplicas:            deploymentReplicas,
 	}
 
 	return factory.New().WithSync(controller.sync).
@@ -93,6 +99,10 @@ func (n *klusterletCleanupController) sync(ctx context.Context, controllerContex
 		_, err := n.patcher.AddFinalizer(ctx, klusterlet, desiredFinalizers...)
 		return err
 	}
+	replica := n.deploymentReplicas
+	if replica <= 0 {
+		replica = helpers.DetermineReplica(ctx, n.kubeClient, klusterlet.Spec.DeployOption.Mode, n.kubeVersion, n.controlPlaneNodeLabelSelector)
+	}
 	// Klusterlet is deleting, we remove its related resources on managed and management cluster
 	config := klusterletConfig{
 		KlusterletName:            klusterlet.Name,
@@ -105,7 +115,7 @@ func (n *klusterletCleanupController) sync(ctx context.Context, controllerContex
 		HubKubeConfigSecret:       helpers.HubKubeConfig,
 		ExternalServerURL:         getServersFromKlusterlet(klusterlet),
 		OperatorNamespace:         n.operatorNamespace,
-		Replica:                   helpers.DetermineReplica(ctx, n.kubeClient, klusterlet.Spec.DeployOption.Mode, n.kubeVersion),
+		Replica:                   replica,
 
 		ExternalManagedKubeConfigSecret:             helpers.ExternalManagedKubeConfig,
 		ExternalManagedKubeConfigRegistrationSecret: helpers.ExternalManagedKubeConfigRegistration,

pkg/operator/operators/klusterlet/controllers/klusterletcontroller/klusterlet_controller.go

@@ -45,14 +45,16 @@ const (
 )
 
 type klusterletController struct {
-	patcher                      patcher.Patcher[*operatorapiv1.Klusterlet, operatorapiv1.KlusterletSpec, operatorapiv1.KlusterletStatus]
-	klusterletLister             operatorlister.KlusterletLister
-	kubeClient                   kubernetes.Interface
-	kubeVersion                  *version.Version
-	operatorNamespace            string
-	skipHubSecretPlaceholder     bool
-	cache                        resourceapply.ResourceCache
-	managedClusterClientsBuilder managedClusterClientsBuilderInterface
+	patcher                       patcher.Patcher[*operatorapiv1.Klusterlet, operatorapiv1.KlusterletSpec, operatorapiv1.KlusterletStatus]
+	klusterletLister              operatorlister.KlusterletLister
+	kubeClient                    kubernetes.Interface
+	kubeVersion                   *version.Version
+	operatorNamespace             string
+	skipHubSecretPlaceholder      bool
+	cache                         resourceapply.ResourceCache
+	managedClusterClientsBuilder  managedClusterClientsBuilderInterface
+	controlPlaneNodeLabelSelector string
+	deploymentReplicas            int32
 }
 
 type klusterletReconcile interface {
@@ -78,18 +80,22 @@ func NewKlusterletController(
 	appliedManifestWorkClient workv1client.AppliedManifestWorkInterface,
 	kubeVersion *version.Version,
 	operatorNamespace string,
+	controlPlaneNodeLabelSelector string,
+	deploymentReplicas int32,
 	recorder events.Recorder,
 	skipHubSecretPlaceholder bool) factory.Controller {
 	controller := &klusterletController{
 		kubeClient: kubeClient,
 		patcher: patcher.NewPatcher[
 			*operatorapiv1.Klusterlet, operatorapiv1.KlusterletSpec, operatorapiv1.KlusterletStatus](klusterletClient),
-		klusterletLister:             klusterletInformer.Lister(),
-		kubeVersion:                  kubeVersion,
-		operatorNamespace:            operatorNamespace,
-		skipHubSecretPlaceholder:     skipHubSecretPlaceholder,
-		cache:                        resourceapply.NewResourceCache(),
-		managedClusterClientsBuilder: newManagedClusterClientsBuilder(kubeClient, apiExtensionClient, appliedManifestWorkClient, recorder),
+		klusterletLister:              klusterletInformer.Lister(),
+		kubeVersion:                   kubeVersion,
+		operatorNamespace:             operatorNamespace,
+		skipHubSecretPlaceholder:      skipHubSecretPlaceholder,
+		cache:                         resourceapply.NewResourceCache(),
+		managedClusterClientsBuilder:  newManagedClusterClientsBuilder(kubeClient, apiExtensionClient, appliedManifestWorkClient, recorder),
+		controlPlaneNodeLabelSelector: controlPlaneNodeLabelSelector,
+		deploymentReplicas:            deploymentReplicas,
 	}
 
 	return factory.New().WithSync(controller.sync).
@@ -179,6 +185,11 @@ func (n *klusterletController) sync(ctx context.Context, controllerContext facto
 		return err
 	}
 
+	replica := n.deploymentReplicas
+	if replica <= 0 {
+		replica = helpers.DetermineReplica(ctx, n.kubeClient, klusterlet.Spec.DeployOption.Mode, n.kubeVersion, n.controlPlaneNodeLabelSelector)
+	}
+
 	config := klusterletConfig{
 		KlusterletName:                         klusterlet.Name,
 		KlusterletNamespace:                    helpers.KlusterletNamespace(klusterlet),
@@ -192,7 +203,7 @@ func (n *klusterletController) sync(ctx context.Context, controllerContext facto
 		HubKubeConfigSecret:                    helpers.HubKubeConfig,
 		ExternalServerURL:                      getServersFromKlusterlet(klusterlet),
 		OperatorNamespace:                      n.operatorNamespace,
-		Replica:                                helpers.DetermineReplica(ctx, n.kubeClient, klusterlet.Spec.DeployOption.Mode, n.kubeVersion),
+		Replica:                                replica,
 		PriorityClassName:                      helpers.AgentPriorityClassName(klusterlet, n.kubeVersion),
 		AppliedManifestWorkEvictionGracePeriod: getAppliedManifestWorkEvictionGracePeriod(klusterlet),
 

pkg/operator/operators/klusterlet/options.go

@@ -25,7 +25,9 @@ import (
 )
 
 type Options struct {
-	SkipPlaceholderHubSecret bool
+	SkipPlaceholderHubSecret      bool
+	ControlPlaneNodeLabelSelector string
+	DeploymentReplicas            int32
 }
 
 // RunKlusterletOperator starts a new klusterlet operator
@@ -96,6 +98,8 @@ func (o *Options) RunKlusterletOperator(ctx context.Context, controllerContext *
 		workClient.WorkV1().AppliedManifestWorks(),
 		kubeVersion,
 		helpers.GetOperatorNamespace(),
+		o.ControlPlaneNodeLabelSelector,
+		o.DeploymentReplicas,
 		controllerContext.EventRecorder,
 		o.SkipPlaceholderHubSecret)
 
@@ -109,6 +113,8 @@ func (o *Options) RunKlusterletOperator(ctx context.Context, controllerContext *
 		workClient.WorkV1().AppliedManifestWorks(),
 		kubeVersion,
 		helpers.GetOperatorNamespace(),
+		o.ControlPlaneNodeLabelSelector,
+		o.DeploymentReplicas,
 		controllerContext.EventRecorder)
 
 	ssarController := ssarcontroller.NewKlusterletSSARController(